Academic literature on the topic 'Energy harvesting relays'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Energy harvesting relays.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Energy harvesting relays"

1

Ho-Van, Khuong, and Thiem Do-Dac. "Security Enhancement for Energy Harvesting Cognitive Networks with Relay Selection." Wireless Communications and Mobile Computing 2020 (September 29, 2020): 1–13. http://dx.doi.org/10.1155/2020/8867148.

Full text
Abstract:
Relay selection is proposed in this paper as an efficient solution to secure information transmission of secondary users against eavesdroppers in energy harvesting cognitive networks. The proposed relay selection method selects a secondary relay among available secondary relays, which are capable of harvesting radio frequency energy in signals of the secondary transmitter and correctly restore secondary message, to curtail signal-to-noise ratio at the wire-tapper. In order to evaluate the security performance of the suggested relay selection method, an exact intercept outage probability formula accounting for peak transmit power confinement, Rayleigh fading, and interference power confinement is firstly derived. Monte-Carlo simulations are then generated to corroborate the proposed formula. Numerous results expose that positions of relays, the number of relays, and parameters of the energy harvesting method significantly influence the security performance while the power confinements on secondary transmitters cause the performance saturation.
APA, Harvard, Vancouver, ISO, and other styles
2

Pan, Huifang, and Qi Zhu. "Energy-Efficient Power Allocation in Non-Linear Energy Harvesting Multiple Relay Systems." Algorithms 14, no. 5 (May 17, 2021): 155. http://dx.doi.org/10.3390/a14050155.

Full text
Abstract:
In this paper, to maximize the energy efficiency (EE) in the two-hop multi-relay cooperative decoding and forwarding (DF) system for simultaneous wireless information and power transmission (SWIPT), an optimal power allocation algorithm is proposed, in which the relay energy harvesting (EH) adopts a nonlinear model. Under the constraints, including energy causality, the minimum transmission quality of information and the total transmission power at the relays, an optimization problem is constructed to jointly optimize the transmit power and power-splitting (PS) ratios of multiple relays. Although this problem is a nonlinear fractional programming problem, an iterative algorithm is developed to obtain the optimal power allocation. In particular, the joint power allocation at multiple relays is first decoupled into a single relay power allocation, and then single-relay power allocation is performed by the Dinkelbach iteration algorithm, which can be proven that it is a convex programming problem. Its closed form solutions for different polylines of EH models are obtained by using mathematical methods, such as monotonicity, Lagrange multipliers, the KKT condition and the Cardan formula. The simulation results show the superiority of the power allocation algorithm proposed in this paper in terms of EE.
APA, Harvard, Vancouver, ISO, and other styles
3

Press, Rifqah, and Vipin Balyan. "Outage probability for a multiuser NOMA-based network using energy harvesting relays." Nonlinear Engineering 11, no. 1 (January 1, 2022): 672–79. http://dx.doi.org/10.1515/nleng-2022-0240.

Full text
Abstract:
Abstract This article evaluates the energy-harvesting capabilities of a multiuser non-orthogonal multiple access-based system, where energy harvesting relays utilise the power splitting relaying protocol to harvest energy and amplify-and-forward protocol to forward the signals to the connected users. The expressions for each user’s energy harvesting outage probability are calculated and compared to the same system model without energy harvesting. Simulation results show the effectiveness of the energy-harvesting relay nodes and the improved outage probability of each user.
APA, Harvard, Vancouver, ISO, and other styles
4

Ho-Van, Khuong, and Thiem Do-Dac. "Relay Selection for Security Improvement in Cognitive Radio Networks with Energy Harvesting." Wireless Communications and Mobile Computing 2021 (June 19, 2021): 1–16. http://dx.doi.org/10.1155/2021/9921782.

Full text
Abstract:
This paper selects an unlicensed relay among available self-powered relays to not only remain but also secure information transmission from an unlicensed source to an unlicensed destination. The relays harvest energy in signals of the unlicensed source and the licensed transmitter. Then, they spend the harvested energy for their relaying operation. Conditioned on the licensed outage restriction, the peak transmission power restriction, Rayleigh fading, and the licensed interference, the current paper proposes an exact closed-form formula of the secrecy outage probability to quickly evaluate the secrecy performance of the proposed relay selection method in cognitive radio networks with energy harvesting. The proposed formula is corroborated by computer simulations. Several results illustrate the effectiveness of the relay selection in securing information transmission. Additionally, the security capability is saturated at large peak transmission powers or large preset outage probabilities of licensed users. Furthermore, the security capability depends on many specifications among which the power splitting ratio, the relays’ positions, and the time switching ratio can be optimally selected to obtain the best security performance.
APA, Harvard, Vancouver, ISO, and other styles
5

Liu, Kang, Qi Zhu, and Ying Wang. "Outage Analysis and Power Allocation Optimization for Multiple Energy-Harvesting Relay System Using SWIPT." Mobile Information Systems 2018 (September 13, 2018): 1–11. http://dx.doi.org/10.1155/2018/7102427.

Full text
Abstract:
Energy harvesting (EH) combined with cooperative relying plays a promising role in future wireless communication systems. We consider a wireless multiple EH relay system. All relays are assumed to be EH nodes with simultaneous wireless and information transfer (SWIPT) capabilities, which means the relays are wirelessly powered by harvesting energy from the received signal. Each EH node separates the input RF signal into two parts which are, respectively, for EH and information transmission using the power splitting (PS) protocol. In this paper, a closed-form outage probability expression is derived for the cooperative relaying system based on the characteristic function of the system’s probability density function (PDF) with only one relay. With the approximation of the outage probability expression, three optimization problems are built to minimize the outage probability under different constraints. We use the Lagrange method and Karush–Kuhn–Tucker (KKT) condition to solve the optimization problems to jointly optimize the relay’s PS factors and the transmit power. Numerical results show that our derived expression of the outage probability is accuracy and gives insights into the effect of various system parameters on the performance of protocols. Meanwhile, compared with the no optimal condition, our proposed optimization algorithms can all offer superior performance under different system constraints.
APA, Harvard, Vancouver, ISO, and other styles
6

Andrawes, Admoon, Rosdiadee Nordin, and Mahamod Ismail. "Wireless Energy Harvesting with Cooperative Relaying under the Best Relay Selection Scheme." Energies 12, no. 5 (March 7, 2019): 892. http://dx.doi.org/10.3390/en12050892.

Full text
Abstract:
One of the most notable challenges in wireless communications is energy scarcity, which has attracted considerable attention in Fifth Generation (5G) wireless network research. This paper investigates the performance of energy harvesting (EH) relays under the best relay selection (BRS) scheme. The results show degradation of spectral efficiency (SE) due to EH relaying compared with conventional cooperative relaying (CR). Conversely, EH relaying provides a positive gain compared with conventional CR, increasing the lifetime of the network and decreasing energy consumption (EC) and operational cost. Moreover, the EH relaying network has better energy efficiency (EE) compared with conventional relaying networks. Results show that when EH relaying is applied, EE is improved through an increased number of relays. Finally, the SE-EE metric is presented for both conventional and EH relays. Results show that the performance of the proposed technique was able to achieve a maximum SE of 1.4 bits/s/Hz and maximum EE at 0.6 bits/s/Hz, and for the case of conventional relays, a maximum SE of 2 bits/s/Hz and EE at 1.1 bits/s/Hz. This result implies that the proposed EH scheme provides an optimum solution for energy-constrained wireless CR systems.
APA, Harvard, Vancouver, ISO, and other styles
7

Liu, Kuang-Hao, and Te-Lin Kung. "Performance Improvement for RF Energy-Harvesting Relays via Relay Selection." IEEE Transactions on Vehicular Technology 66, no. 9 (September 2017): 8482–94. http://dx.doi.org/10.1109/tvt.2017.2692804.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Messadi, Oussama, Aduwati Sali, Vahid Khodamoradi, Asem A. Salah, Gaofeng Pan, Shaiful J. Hashim, and Nor K. Noordin. "Optimal Relay Selection Scheme with Multiantenna Power Beacon for Wireless-Powered Cooperation Communication Networks." Sensors 21, no. 1 (December 29, 2020): 147. http://dx.doi.org/10.3390/s21010147.

Full text
Abstract:
Unlike the fixed power grid cooperative networks, which are mainly based on the reception reliability parameter while choosing the best relay, the wireless-powered cooperative communication network (WPCCN) and in addition to the reception reliability the transmission requirement consideration is important for relay selection schemes. Hence, enabling efficient transmission techniques that address high attenuation of radio frequency (RF) signals according to the distance without increasing the total transmission power is an open issue worth studying. In this relation, a multiantennas power beacon (PB) that assists wireless-powered cooperative communication network (PB-WPCCN) is studied in this paper. The communication between source and destination is achieved with the aid of multiple relays, where both the source and the multiple relays need to harvest energy from the PB in the first place to enable their transmission functionalities. A novel relay selection scheme is proposed, named as two-round relay selection (2-RRS), where a group of relays that successfully decode the source information is selected in the first round selection. In the second round, the optimal relay is selected to forward the recorded information to the destination. The proposed 2-RRS scheme is compared with two existing relay selection schemes, i.e., partial relay selection (PRS) and opportunistic relay selection (ORS). The analytical closed-form expressions of outage probability and average system throughput are derived and validated by numerical simulation. The comparison results between different relay selection schemes show: (I) The superiority of the proposed 2-RRS scheme as it achieves around 17% better throughput compared to the conventional ORS scheme and 40% better than the PRS scheme, particularly when PB transmit power is 10 dB; (II) The proposed 2-RRS scheme guarantees the lowest outage probability, especially when the PB is equipped with multiantennas and performs beamforming technique; (III) The optimal localisation of the PB between the source and N relays depends on the adopted relay selection scheme; (IV) The exhaustive search of the maximum system throughput value shows that the proposed 2-RRS scheme required shorter energy harvesting time compared to other schemes. The increase in energy harvesting time and number of relays do not necessarily reflect positively on the system throughput performance; hence tradeoffs should be taken into consideration.
APA, Harvard, Vancouver, ISO, and other styles
9

Lin, Ciao-Han, and Kuang-Hao Liu. "Relay Selection for Energy-Harvesting Relays With Finite Data Buffer and Energy Storage." IEEE Internet of Things Journal 8, no. 14 (July 15, 2021): 11249–59. http://dx.doi.org/10.1109/jiot.2021.3053290.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Van Nguyen, Minh-Sang, Dinh-Thuan Do, and Miroslav Voznak. "Improving Performance of Far Users in Cognitive Radio: Exploiting NOMA and Wireless Power Transfer." Energies 12, no. 11 (June 10, 2019): 2206. http://dx.doi.org/10.3390/en12112206.

Full text
Abstract:
In this paper, we examine non-orthogonal multiple access (NOMA) and relay selection strategy to benefit extra advantage from traditional cognitive radio (CR) relaying systems. The most important requirement to prolong lifetime of such network is employing energy harvesting in the relay to address network with limited power constraint. In particular, we study such energy harvesting CR-NOMA using amplify-and-forward (AF) scheme to improve performance far NOMA users. To further address such problem, two schemes are investigated in term of number of selected relays. To further examine system performance, the outage performance needs to be studied for such wireless powered CR-NOMA network over Rayleigh channels. The accurate expressions for the outage probability are derived to perform outage comparison of primary network and secondary network. The analytical results show clearly that position of these nodes, transmit signal to noise ratio (SNR) and power allocation coefficients result in varying outage performance. As main observation, performance gap between primary and secondary destination is decided by both power allocation factors and selection mode of single relay or multiple relays. Numerical studies were conducted to verify our derivations.
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Energy harvesting relays"

1

Elmorshedy, Lina. "RF energy harvesting in a decode-and-forward wireless relay network." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57607.

Full text
Abstract:
Wireless communication has experienced tremendous growth over the past three decades. This led to the development of many novel technologies aimed at enhancing the system performance due to the limited availability of radio resources. Cooperative relaying is a promising technology which enhances transmission reliability using simple hardware. However, the extra power consumed for the process of information relaying may be an issue. Recent advances in wireless energy transfer have made it possible for self-sustainable relays that power themselves by capturing ambient energy wirelessly. In this thesis we focus on two technologies, namely, cooperative relaying which enhances the energy efficiency and reliability by allowing multi-hop communication with low power nodes, and Radio Frequency (RF) energy harvesting which obviates the need for a battery by capturing the ambient RF energy and using it as a source power. In the first part of the thesis, we study RF energy harvesting in a Decode-and-Forward (DF) Wireless Relay Network (WRN) in the presence of an interferer node. We consider the Time Switching Relaying (TSR) protocol, the Power Splitting Relaying (PSR) protocol and we propose a new hybrid TSR-PSR protocol. We derive expressions for the outage probability and throughput in the delay-sensitive transmission mode for the three relaying protocols, and compare their performances. For simplicity, we neglect the energy harvested from the interferer signal. In the second part, we study the general case in which we include the effect of harvesting energy from the interferer signal. Expressions for the outage probability and throughput in the delay-sensitive transmission mode are derived for the three relaying protocols. Numerical results are presented to illustrate the effect of including RF energy harvesting from the interferer. In the third part, we study shared and non-shared power allocation schemes for a two-hop DF WRN with multiple source-destination pairs. The pairs communicate via a single relay which harvests RF energy from the source transmissions in the presence of an interfering signal. The studied schemes are compared in terms of outage probability, throughput in the delay-sensitive transmission mode and fairness.
Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
APA, Harvard, Vancouver, ISO, and other styles
2

Arab, Loodaricheh Roya. "Resource allocation in wireless systems with relay-based cooperation and energy harvesting." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/55917.

Full text
Abstract:
Wireless communication networks are subject to exponential growth as a result of proliferation of smart phones, diverse wireless services and Internet of Things (IoT) applications. This extensive growth of wireless networks can significantly increase energy consumption, and escalating environmental pollution and energy costs have already created an urge for green communication. Therefore, we need to be proactive in designing environment friendly communication technologies and efficient resource allocation solutions, which will potentially drive the future generation of wireless communication. In this thesis, we focus on two promising communication technologies, namely cooperative relaying, which improves energy and spectral efficiency by providing spatial diversity, and energy harvesting technology, which can improve sustainability by utilizing renewable energy sources. The objective of this thesis is to address a number of key challenges in the design of efficient resource allocation techniques for wireless systems based on these two communication technologies. Firstly, we address the problem of energy efficiency maximization for downlink orthogonal frequency division multiple access (OFDMA)-based cooperative networks. The power and subcarrier allocation policies are jointly optimized with quality of service (QoS) provisioning. Afterwards, we investigate frequency reuse in OFDMA device-to-device (D2D) cooperative systems in which D2D pairs are classified based on the level of proximity with each other. We propose different scenarios of downlink communications and provide efficient frequency allocation techniques. Moreover, resource allocation algorithms with low complexity and signaling overhead are developed. Next, we focus on energy limitation of the relay nodes in cooperative systems. Using wireless energy harvesting to power the relay nodes, we propose an efficient resource allocation algorithm. As wireless energy harvesting technology is only effective for charging small nodes in communication systems, finally, we focus on the issue of charging the wireless nodes with renewable energy. We investigate the problem of resource allocation in energy harvesting systems considering the fact that the energy harvested from environment may not be enough to satisfy the QoS of all users due to its random nature. Two different utility functions are introduced and both offline and online schemes are devised to address this problem.
Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
APA, Harvard, Vancouver, ISO, and other styles
3

Li, Ziyi. "Wireless-Powered Communication with Energy Accumulation." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16123.

Full text
Abstract:
In this thesis, I focus on the system design and performance analysis of wireless communication networks with radio frequency (RF) energy harvesting. Battery re-placement/recharging has always been a challenging issue in wireless communication networks, especially in large-scale networks like wireless sensor networks (WSNs). Recently, RF energy harvesting (EH) technology has been developed as a new viable solution to extend the lifetime of wireless networks via enabling wireless devices to harvest energy from RF signals. Inspired by this technique, wireless-powered communication networks (WPCNs) have attracted an upsurge of research interest. According to the protocols proposed in current literature, an EH user will exhaust all the energy it harvests straightway during this transmission block. This may be a sub-optimal solution, since this little amount of energy may not be able to contribute to an effective transmission. Therefore, in this thesis, I consider energy accumulation at each EH node by providing an energy storage (e.g. a rechargeable battery), so that it can an accumulate sufficient amount of harvested energy before transmission and wait to transmit in an appropriate time slot. To begin with, I first investigate wireless energy harvesting (WEH) technique in cooperative communication networks where the source and relay can both communicate with the destination. I refer to this kind of network as wireless-powered cooperative communication networks (WPCCNs). This WEH technique offers a new cooperation manner for wireless devices since the relay node is now able to harvest energy from the source’s information. In this thesis, I consider the relay as a wireless-powered node that has no external power supply; but it is equipped with an EH unit and a rechargeable battery so that it can harvest and accumulate energy from RF signals broadcast by the source. By fully incorporating the EH feature of the relay, an opportunistic relaying protocol was developed, termed accumulate-then-forward (ATF), for the considered WPCCN with a direct link. The discrete Markov chain is adopted to model the dynamic charging and discharging behaviors of the relay battery. Based on this, I derive a closed-form expression for the exact system outage probability of the proposed ATF protocol. Numerical results show that the ATF scheme can outperform the direct transmission one, especially when the amount of energy consumed by the relay for information forwarding is optimized. In order to further take advantage of the direct link between the source and destination, an incremental accumulate-then-forward (IATF) scheme was proposed to the considered WPCCNs. In the IATF protocol, the source sends its information to the destination via the direct link and requests the relay to cooperate only when it is necessary, such that the relay has more chances to accumulate energy. By modelling the charging/discharging behaviors of the relay battery as a finite-state Markov chain, I derive a closed-form expression for the system outage probability of the proposed IATF. Numerical results validate my theoretical analysis and show that the IATF scheme can significantly outperform the direct transmission scheme without cooperation and the ATF scheme. A comparison of these two schemes is also given to show examples of their advantages and disadvantages. One of the key features of WEH technique is one-to-many, where multiple EH nodes can harvest energy simultaneously from one single RF signal. The energy from broadcasted RF signals can thus be transferred to several EH nodes rather than only one EH node, which can increase the energy transfer efficiency of the whole communication network. Contrast to the single EH node previously, in the last chapter of this thesis, I investigate a WPCN with multiple EH nodes and focus on the multi-user scheduling problem. I assume a power beacon (PB) is deployed in WPCN dedicating to charge the EH nodes by broadcasting RF energy signals. With this PB-assisted WEH technique, the considered WPCN consists of a PB, an access point (AP) and multiple EH users attempting to transmit information toward the AP. In this thesis, I consider that only one EH user can be selected to forward its information, and the rest of the nodes will continue to harvest energy. In order to harvest energy effectively and transmit information efficiently, I proposed several types of multi-user scheduling schemes based on the availability of the channel state information (CSI), i.e. multi-user scheduling scheme without CSI, multi-user scheduling scheme using channel state information at the receiver (CSIR), and multi-user scheduling scheme using channel state information at the transmitter (CSIT). Two more Proportional Fairness scheduling schemes are proposed in order to achieve the fairness among all the EH users. Simulation results show that the availability of CSI can significantly improve the access outage probability, where the average probability of the user successfully connect to the AP is shown. Moreover, the fairness among different users can be dramatically improved by two Proportional Fairness schemes.
APA, Harvard, Vancouver, ISO, and other styles
4

Nguyen, K. G. (Kien-Giang). "Energy-efficient transmission strategies for multiantenna systems." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526222677.

Full text
Abstract:
Abstract The rapid evolution of wireless networks to meet the requirements of explosive data traffic demand is escalating energy consumption beyond sustainable limits. Consequently, energy efficiency (EE) has emerged as a key performance indicator for future wireless networks to address the increasing concern over greenhouse gas emissions and sustainable economic growth. This thesis studies energy-efficient transmission strategies for multiantenna wireless systems. The aim is to develop linear beamforming techniques maximizing the bit-per-Joule EE metric, focusing on three appealing scenarios: a coordinated multicell system; a fronthaul-constrained cloud radio access network (C-RAN); and a multi-pair wireless-powered relaying system. The primary emphasis is on suboptimal but efficient optimization approaches which are attractive for practical implementation. The problem of achieving EE fairness in a multicell multiple-input single-output downlink system is studied first. Specifically, coordinated beamforming is designed to maximize the minimum EE among all base stations. Novel efficient iterative optimization methods solving the design problem in both centralized and decentralized fashions are proposed. In a downlink C-RAN with finite-capacity fronthaul links, the network-wide EE performance is explored via a joint design of beamforming and remote radio head-user association. A relatively realistic power consumption model including rate-dependent circuit power and nonlinear power amplifiers' (PA) efficiency is also considered. To gain an insight into the optimal performance of the design problem, an algorithm achieving globally optimal solutions is devised. Towards practical implementation, two efficient iterative suboptimal methods are proposed aiming at yielding near-optimal performance. Finally, a multi-pair amplify-forward relaying network is considered, in which energy-constrained relays adopting time-switching protocol harvest energy from the radio frequency signals transmitted by users. To maintain EE fairness among all user pairs, joint optimization of system parameters, such as users' transmit power, relay beamforming, and energy harvesting (EH) time, is studied. Impacts of rate-dependent circuit power, nonlinear PAs' efficiency and nonlinear EH circuits on the achievable performance are also addressed
Tiivistelmä Langattomat verkot ovat kehittyneet nopeasti räjähdysmäisesti kasvavan dataliikenteen mahdollistamiseksi, minkä seurauksena energiankulutus on kasvanut kestävän kehityksen rajat ylittävällä tavalla. Siksi energiatehokkuudesta (EE, energy efficiency) on tullut uusien langattomien verkkojen keskeinen suunnittelukriteeri vastauksena kasvavaan huoleen kasvihuonepäästöistä ja kestävästä talouskasvusta. Väitöskirjassa tutkitaan moniantennisten langattomien järjestelmien energiatehokkaita tiedonsiirtostrategioita. Tavoitteena on kehittää lineaarisia keilanmuodostustekniikoita, jotka maksimoivat energiatehokkuuden mitattuna bitteinä joulea kohden, keskittymällä kolmeen kiinnostavaan vaihtoehtoon, joita ovat koordinoitu monisolujärjestelmän lähetys laskevalla siirtotiellä, pilvipohjainen radioliityntäverkko (C-RAN, cloud radio access network), jossa laskentayksikön ja varsinaisen radiolähettimen välinen yhteys (fronthaul) on rahoitettu, ja usean parin relejärjestelmiin, joissa releet toimivat paristoilla. Työn pääpaino on alioptimaalisissa, mutta käytännöllisesti tehokkaissa optimointimenetelmissä. Pääpaino on alioptimaalisissa mutta tehokkaissa optimointitavoissa, jotka ovat kiinnostavia käytännön toteutuksen näkökulmasta. Ensiksi tarkastellaan tasapuolisen energiatehokkuuden saavuttamista monisoluisessa laskevan siirtotien moni-tulo yksi-lähtö (MISO, multiple-input single-output) -järjestelmässä. Koordinoitu keilanmuodostus on suunniteltu erityisesti maksimoimaan energiatehokkuuden minimitaso kaikilla tukiasemilla. Tarkemmin sanottuna pyritään maksimoimaan huonoin energiatehokkuus solmujen välillä, kun käytetään yhteistoiminnallista keilanmuodostusta. Muodostetun ongelman ratkaisemiseksi ehdotetaan edistyksellisiä iteratiivisia menetelmiä käyttämällä sekä keskitettyjä että hajautettuja ratkaisuja. Laskevan siirtosuunnan fronthaul-rajoitetussa C-RAN-järjestelmässä selvitetään verkonlaajuista energiatehokkuutta keilanmuodostuksen ja palvelevan tukiaseman yhteisoptimoinnilla. Tässä käytetään verrattain realistista tehonkulutusmallia, joka sisältää datanopeudesta riippuvan prosessointitehon ja epälineaarisen tehovahvistimen (PA, power amplifier) hyötysuhteen. Jotta saadaan käsitys ongelman optimaalisesta suorituskyvystä, siihen kehitetään globaalisti optimaalinen menetelmä. Lisäksi ehdotetaan kaksi käytännöllisempää iteratiivista menetelmää, jotka saavuttavat lähes optimaalisen suorituskyvyn. Lopuksi keskitytään monen parin vahvista-ja-välitä eteenpäin (AF. amplify and forward) verkkoon, jossa aikajakokytkentää käyttävät energiarajoitetut toistimet keräävät energiaa käyttäjien lähettämistä radiosignaaleista. Jotta saavutetaan EE:n oikeudenmukaisuus kaikkien parien välillä, parametrit, kuten käyttäjien lähetysteho, toistimen keilanmuodostus, ja energiankeräysaika suunnitellaan yhdessä. Tässä tutkitaan nopeusriippuvaisen piirin tehon, epälineaarisen tehovahvistimen hyötysuhteen ja epälineaaristen energiankeräyspiirien tehon vaikutusta suorituskykyyn
APA, Harvard, Vancouver, ISO, and other styles
5

Sudhakar, Modem. "Optimization of networks with energy harvesting relays." Thesis, 2018. http://localhost:8080/xmlui/handle/12345678/7582.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Te-LinKung and 孔德琳. "Relay Selection and Block Scheduling for Energy Harvesting Relays Based on Time Division Multiplexing." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/05259961840669336141.

Full text
Abstract:
碩士
國立成功大學
電腦與通信工程研究所
103
Energy harvesting (EH) is an attractive solution to prolong the lifetime of wireless devices. As the replacement of traditional battery-powered relay nodes, EH relays extract energy from the signal of the source node and use the harvested energy to perform information relaying, enabling a self-sustainable cooperative network. To use the harvested energy efficiently which is limited due to the energy loss by wireless channel impairment and RF-DC conversion, it is important to properly schedule the two tasks for relays, namely information and EH, within a transmission block. In this thesis, we investigate block scheduling and relay selection problems in a cooperative networks with EH relays. In terms of block scheduling, we consider two variants of time division multiplexing, including partial time reuse and full-duplex scheduling. In terms of relay selection, we propose a relay selection scheme where selected max-max relay selection (S-MMRS) considers both the source-relay channel for EH and the relay-destination channel for information relaying in selecting the cooperating relay. To evaluate the performance of the proposed S-MMRS, we theoretically analyze the outage probability and the throughput and the simulation results are presented to verify the analysis accuracy and demonstrate the impact of system parameters to the proposed relay selection scheme.
APA, Harvard, Vancouver, ISO, and other styles
7

Lin, Yean-ping, and 林晏平. "Lifetime Maximization in AF Cooperative Networks with Energy-Harvesting Relays." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8c2etv.

Full text
Abstract:
碩士
國立中山大學
通訊工程研究所
103
In this thesis, we consider AF cooperative networks with multiple radio frequency energy-harvesting (RFEH) relays, and investigate power allocation and relay selection strategies to prolong the network lifetime since relays are battery-powered with limited energy. Through cooperation among multiple relays, reliability and transmission rate of cooperative networks are enhanced by exploiting spatial diversity. If relays rely on wireline power supplies, implementation cost must increase and mobility is lacked. Therefore, we consider relays apply RFEH technology to harvest energy by transferring ambient RF signal into electrical energy, so that they can be self-sustained. Consequently, the network lifetime can be further prolonged. In this thesis, we investigate relay selection strategies to choose one relay to forward messages while the others perform energy harvesting. Those selection strategies aim to minimize the loss of energy dissipation, reducing wasted energy and increase the average harvested energy, in order to prolong the network lifetime. In this thesis, we define network lifetime based on the outage performance of the network. Specifically, if outage probability of network is lower than a threshold, the system is treated as &;quot;well-functioned&;quot;, and the network lifetime is defined as the longest period in which network is well-functioned. From the expression of outage probability, network lifetime is related to the residual energy of relays.Compares with existing relay selection strategies which take Channel State Information(CSI),Residual Energy Information(REI), and/or Harvested Energy Information(HEI) into account, we proposed a novel relay selection scheme based on opportunity cost of each choice. Because the proposed scheme properly exploits CSI, REI, and HEI, the proposed scheme outperforms others with stringent outage requirement. Moreover, since all relay selection strategies require simply local CSI, REI, and HEI, they can be accomplished in a distributed manner through opportunistic carrier sensing without extra overhead.
APA, Harvard, Vancouver, ISO, and other styles
8

Yu-HsienLi and 李郁賢. "Cooperative Relay Selection Scheme based on Wireless Energy Harvesting." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15346663975401734418.

Full text
Abstract:
碩士
國立成功大學
電腦與通信工程研究所
102
The use of energy harvesting (EH) nodes as cooperative relays is a promising and emerging solution for energy limited wireless systems, rendering the network self-sustaining with significantly prolonged lifetime. In this thesis, we consider multiple EH relay nodes harvesting energy from the radio frequency (RF) signal received from the source and use that harvested energy to forward the source information to the destination. Unlike conventional wireless nodes relied on fixed power supplies, EH relays may not be permanently available to assist the source transmission due to the limited energy conversion efficiency, the mismatch between the charging and discharging profiles, and the finite energy storage capacity. Our objective is to improve the reliability of EH relays by properly selecting one relay to perform data forwarding while the remaining relays perform energy harvesting. We propose the ``battery-aware relay selection (BARS)', which jointly considers the channel condition and the buffer status for relay selection. The outage probability of the proposed scheme is analyzed based on a Markov chain model. Simulations are performed to validate the analysis accuracy. The proposed scheme is compared with the ``CSI-based relay selection scheme', which selects the cooperating relay only based on the channel condition. Through numerical results, we show that the CSI-based scheme suffers error floor while the propose BARS scheme can achieve the full diversity order equal to the number of relays without the need of fixed power cables.
APA, Harvard, Vancouver, ISO, and other styles
9

Mashiri, Tatenda Kuwarika. "Relay selection in massive MIMO wireless energy harvesting cognitive networks." Thesis, 2020. https://hdl.handle.net/10539/31118.

Full text
Abstract:
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2020
In recent years, there has been an explosive growth in bandwidth-hungry wireless devices and applications which has, in turn, caused a strain on the provisions of the present electromagnetic spectrum. Several technologies have been studied and implemented in the quest to try and alleviate this growing scarcity of the spectrum. This work, therefore, tries to address some of these challenges by looking at spectrum utilisation techniques and how optimal they can be implemented to improve the spectral efficiency and overall system performance. This research seeks to investigate the sum-rate and outage performance of an energy harvesting cognitive massive multiple-input multiple-output (MIMO) multi-relay assisted network with underlay spectrum sharing. The secondary network is permitted to opportunistically access the licenced primary network frequency band provided that the intra-cell interference imposed on the primary base station due to concurrent secondary network transmissions does not exceed the pre-set interference temperature and hence maintain the quality-of-service (QoS) requirements of the primary network. The introduction of relays improves the system performance by increasing the network coverage and this research analyses the performance of the cognitive relay networks by looking at (i) the effect of primary user interference on the relay and subsequently relay selection, (ii) the outage probability of the secondary network being assisted by an amplify-and-forward (AF) relay and (iii) the impact of the number of relay antennas and the number of relays. The power-constrained secondary network nodes harvest energy from concurrent transmissions of the energy sufficient primary users. A time switching protocol is implemented in this work for energy harvesting and closed-form expressions for the harvested energy and achievable sum-rate are derived. To that end, this research seeks to quantify the trade-off between the achievable sum-rate of the network and the harvested energy. The primary base station and secondary destination employ zero-forcing detection and performance is investigated over Rayleigh fading
CK2021
APA, Harvard, Vancouver, ISO, and other styles
10

Chiu, Han-Chiuan, and 邱翰銓. "Precoding Design in Two-Way Cooperative System with Energy Harvesting Relay." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/64785606245180005933.

Full text
Abstract:
碩士
國立中山大學
電機工程學系研究所
102
Due to rapid development of mobile communications, radio-frequency signals are surrounded in our environment. Besides conveying information, the ambient radio-frequency signal has gradually been utilized for energy harvesting. Radio Frequency energy harvesting begins from the fact that people gradually rely on mobile applications, such as communication apps., picturing software, and games, in their daily life. However, these applications are energy consuming. Although these devices can be charged through portable power bank, the energy stored in the power bank is still limited, which leads to inconvenience when the power bank is in outage. To provide further convenience, RF energy harvesting has been developed to avoid mobile devices suffering power outage by gathering energy from from the ambient radio frequency signals and transferring into electricity. Furthermore, simultaneously processing information and harvesting energy from the RF signal has been studied extensively in recent years. In this thesis, we will employ this technique in two-way amplify-and-forward relay system, where two users exchange information under assistance of an energy-harvesting relay node. Specifically speaking, transmission power of the relay node depends on the electrical energy harvested in previous phase. We assume that the relay node is equipped with two antennas, while the users are equipped with a single antenna. With perfect channel information, the relay node can coherently combines the signals received at two antennas, so that the relay node is able to gather more energy. In this thesis, we proposed a joint design of a precoding matrix and power-slitting ratios for the relay node to maximize the sum-rate of two users under a constraint that the transmission power of the relay node cannot exceed the harvested energy. However, this optimization problem is neither convex nor concave, and it can’t be solved by CVX tool. Thus, we divide the problem into two sub-problems to approach a locally-optimal solution of the precoding matrix and power-splitting ratios in an iterative manner. Specifically, we employ gradient algorithm to obtain power-splitting ratios with initial value obtained by exhaustively searching over a rough grid. Then, the beamforming matrix is obtained using power iteration algorithm. After several iterations, two subproblems get converged and we can find the set of suboptimal solutions. It shows through simulation results that the proposed scheme can effectively improve the spectrum efficiency of the system.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Energy harvesting relays"

1

Samanta, Dipak, Chanchal Kumar De, and Abhijit Chandra. "Performance Analysis of Energy Harvesting-Based CR Network Assisted by Full-Duplex Relays Under Joint Underlay/Overlay Mode." In Lecture Notes in Electrical Engineering, 617–31. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2710-4_49.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Liang, Guangjun, Jianfang Xin, Qun Wang, Lingling Xia, and Meng Li. "Energy Efficiency Optimization for RF Energy Harvesting Relay System." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 53–66. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68737-3_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Yang, Mengqi, Yonghong Kuo, and Jian Chen. "Relay Selection Scheme for Energy Harvesting Cooperative Networks." In Communications and Networking, 13–22. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-66628-0_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Li, Huijiang, Neeraj Jaggi, and Biplab Sikdar. "Cooperative Relay Scheduling in Energy Harvesting Sensor Networks." In Green IT: Technologies and Applications, 127–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22179-8_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Hu, Wanqiu, Yanxin Yao, Zhengwei Ni, Rajshekhar V. Bhat, and Mehul Motani. "Time-Switching Energy Harvesting Relay Optimizing Considering Decoding Cost." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 663–73. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-48513-9_53.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Zhang, Zhiqiang, Yifei Wei, Bo Gu, Xaojun Wang, and Mei Song. "Energy Harvesting Relay Node Deployment for Network Capacity Expansion." In Human Centered Computing, 301–10. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-74521-3_33.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Yan, Kaiqiang, Guochun Ren, Jin Chen, Guoru Ding, and Huidong Liu. "Optimal Cooperation Strategy in Cognitive Relay Networks with Energy Harvesting." In Proceedings of the 2015 International Conference on Communications, Signal Processing, and Systems, 93–102. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49831-6_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Li, Jianxiong, Ke Zhao, Xianguo Li, Xuelong Ding, and Weiguang Shi. "Research on Interference Energy Harvesting Based on SWIPT Relay System." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 430–39. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-90802-1_38.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Li, Xian, Yulong Han, Qiuling Tang, and Jiahao Shi. "A Relay Protocol in AF Relaying Wireless Energy Harvesting Network." In Advances in Intelligent, Interactive Systems and Applications, 823–29. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-02804-6_107.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Tran, Xuan Nam, Tran Manh Hoang, Nguyen Ba Cao, and Le The Dung. "Outage Performance of the Downlink NOMA Relay Networks with RF Energy Harvesting and Buffer Aided Relay." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 164–77. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05873-9_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Energy harvesting relays"

1

Amarasuriya, Gayan, Shang Liu, and H. Vincent Poor. "Wireless energy harvesting massive MIMO relays." In 2016 IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM). IEEE, 2016. http://dx.doi.org/10.1109/sam.2016.7569750.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kung, Te-Lin, and Kuang-Hao Liu. "Relay Selection for Energy-Harvesting Relays with Short-Term Energy Storage." In GLOBECOM 2016 - 2016 IEEE Global Communications Conference. IEEE, 2016. http://dx.doi.org/10.1109/glocom.2016.7842210.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Lee, Yu-Hsien, and Kuang-Hao Liu. "Battery-aware relay selection for energy-harvesting relays with energy storage." In 2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC). IEEE, 2015. http://dx.doi.org/10.1109/pimrc.2015.7343588.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Luo, Yaming, Jun Zhang, and Khaled B. Letaief. "Achieving energy diversity with multiple energy harvesting relays." In 2014 Sixth International Conference on Wireless Communications and Signal Processing (WCSP). IEEE, 2014. http://dx.doi.org/10.1109/wcsp.2014.6992051.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mheich, Zeina, and Valentin Savin. "Cooperative communication protocols with energy harvesting relays." In 2017 Wireless Days (WD). IEEE, 2017. http://dx.doi.org/10.1109/wd.2017.7918116.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Hejri, Farrokh, Reyhaneh Khabir, and Mohammad Javad Emadi. "Optimal power allocation for parallel relay network with/without energy-harvesting relays." In 2017 Iranian Conference on Electrical Engineering (ICEE). IEEE, 2017. http://dx.doi.org/10.1109/iraniancee.2017.7985398.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Liu, Kuang-Hao. "Outage-optimal relay selection for energy-harvesting relays based on power splitting." In 2015 International Conference on Wireless Communications & Signal Processing (WCSP). IEEE, 2015. http://dx.doi.org/10.1109/wcsp.2015.7341060.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Liu, Kuang-Hao. "Selection cooperation using RF energy harvesting relays with finite energy buffer." In 2014 IEEE Wireless Communications and Networking Conference (WCNC). IEEE, 2014. http://dx.doi.org/10.1109/wcnc.2014.6952643.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Murali, K., and S. Siva Perumal. "Block Consecutive Minimization Method with Wireless Energy Harvesting Relays." In 2018 Third International Conference on Electrical, Electronics, Communication, Computer Technologies and Optimization Techniques (ICEECCOT). IEEE, 2018. http://dx.doi.org/10.1109/iceeccot43722.2018.9001433.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Baidas, Mohammed W. "Energy-Efficiency Maximization in Downlink Clustered NOMA Networks with Energy-Harvesting Relays." In 2020 International Conference on Communications, Signal Processing, and their Applications (ICCSPA). IEEE, 2021. http://dx.doi.org/10.1109/iccspa49915.2021.9385765.

Full text
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography